Blog Post

The Complementary Power of RUM & Internet Synthetic Monitoring

Real user monitoring and Internet synthetic monitoring are two powerful tools that, when used in tandem, offer a comprehensive view of performance and user experience. Read on to find out why.

User expectations are at an all-time high, and any performance hiccups can lead to frustrated users and lost business opportunities. To get real-time insights into their digital assets and succeed in this competitive landscape, businesses need Internet Performance Monitoring (IPM) that incorporates both synthetic and Real User Monitoring (RUM). RUM and synthetics are two powerful tools that, when used in tandem, offer a comprehensive view of performance and user experience.

Understanding RUM and Synthetic Monitoring

Real User Monitoring (RUM) is a passive monitoring technique that captures actual user interactions with your website or application. It gathers data on various parameters, such as page load times, user interactions, and error rates, directly from users’ browsers. RUM provides valuable insights into how real users experience your site, enabling you to identify performance bottlenecks and prioritize optimizations based on real-user behavior.

On the other hand, synthetic monitoring is a proactive approach that simulates user interactions by sending pre-defined requests to your website or application. This monitoring occurs at regular intervals from diverse geographical locations, representing an actual end user’s experience. This method proactively identifies issues before they impact real users, helping you maintain a high level of performance and reliability.  

The Power of Synthetic and RUM Integration

While RUM and synthetic monitoring have unique strengths, their synergy presents a potent amalgamation of advantages:   

  1. Comprehensive Insights for User-Centric Performance: The combination of RUM and synthetics provides a holistic view of performance. RUM captures genuine user experiences, while synthetic monitoring conducts controlled tests from diverse locations. This blend reveals performance across regions and network conditions, guiding optimization efforts.   
  1. Proactive Issue Management and Real User Impact: Synthetic monitoring proactively identifies potential issues before they affect users, allowing timely fixes. RUM complements this by showing real-time user impact, aiding prioritization. Together, this dynamic duo ensures a proactive and user-centered approach to performance management.  
  1. Enhanced Global User Experience and Understanding: Synthetic monitoring ensures consistent global accessibility by assessing performance worldwide. RUM adds context, revealing regional user challenges. This synergy empowers optimizing user experience across the globe while understanding regional nuances.  

Imagine a scenario where a popular e-commerce website experiences a sudden spike in page load times during a sale event. Synthetic monitoring would promptly detect this anomaly, shedding light on technical bottlenecks in the server response and network latency.  

However, the combination with RUM truly paints the complete picture.

RUM would reveal that this delay resulted in a significant drop in user engagement, with shoppers frustrated by sluggish load times abandoning their carts. This real-time user perspective transforms raw synthetic data into a tangible user experience story, enabling businesses to swiftly address the issue, improve overall performance, and secure customer loyalty.

In essence, the partnership between Synthetic and RUM equips organizations with a multidimensional understanding, allowing them to optimize their websites for technical efficiency and genuine user satisfaction.  

Real-world examples: RUM and Synthetics working together

Luxury Brand’s Surprising Page View Drop

On June 27, 2023, one of our customers – a leading luxury brand, used a combination of RUM and Synthetic monitoring to analyze their website. Specifically, they wanted to use RUM data to identify patterns and trends. To their surprise, they discovered a significant decrease in the number of page views. Digging deeper, they assessed metrics such as Largest Contentful Paint and Document Complete, revealing a noticeable spike in both indicators, as shown below:  

north america LCP doc complete charts

Upon closer examination, it became evident that this incident impacted the volume of page views, as indicated by the data for the affected date and time.

page views monitoring chart

Delving deeper, we confirmed that one of the JavaScript files was indeed affected by a prolonged loading time. This, in turn, played a role in the challenges associated with extended document completion and heightened Largest Contentful Paint timings.  

Swift Resolution: Cutting Document Completion Time

In a different scenario, RUM and synthetics worked together to identify an issue with Document Complete due to extended loading times linked to a JavaScript file. After promptly informing the customer about this, they took immediate action and helped us resolve the problem by addressing the problematic JavaScript file.

This collaboration led to a notable improvement, reducing the overall document completion time from 19 seconds to 13 seconds, as depicted in the illustration below:   

doc complete improvement chart

Granular Data Pinpoints Connectivity Issue

A prominent global investment firm started experiencing a drop in page views, but from specific geographical locations.  

real user monitoring data by isp

Insights from RUM and synthetic monitoring helped isolate issue with SSL handshake occurring from a single ISP.  

synthetic user monitoring data with isp


Combining synthetic monitoring with RUM results in a more comprehensive and robust monitoring strategy that provides you with full visibility into the experience of your end users.  

But not all synthetics are created equal.  

Many companies like Datadog, Dynatrace, and AppDynamics provide only web synthetics. What sets Catchpoint’s IPM solution apart is the use of Internet Synthetics to enable comprehensive visibility across the entire Internet Stack. Discover how Internet Synthetics offer deeper, richer insights beyond traditional web synthetics.

To learn more about Catchpoint IPM, download our solution brief.  

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